1. Field of the Invention
The present invention relates to an apatite shaped product useful as an implant material such as an artificial bone or an artificial fang, and a process for its production.
2. Discussion of Background
Bones and teeth of human beings and animals are regarded as being made of apatite complexed with an organic material such as collagen. This apatite can easily be artificially synthesized and will not bring about rejection even when embedded in a vital body. Accordingly, such apatite is presently processed into granules and used as an implant material.
On the other hand, it is known that when apatite is applied in the form of a sintered product to a site where strength is required, the apatite may bond to a bone in a vital body, but when a force is exerted to the bonded portion, a strong stress will be formed at the bonded portion, which will lead to breakage. Therefore, the use is very much limited. This is caused by the fact that the Young's modulus of the sintered product of apatite is about 100 GPa, while the Young's modulus of a bone is as low as at most 20 GPa.
Accordingly, it is desired to modify apatite to be close to a real bone rather than a mere sintered product and to have it complexed with an organic material to lower the Young's modulus. However, this has not been realized before.